Specifies methods for the calculation of the superior calorific value, inferior calorific value, density, relative density and Wobbe index of dry natural gases, natural gas substitutes and other combustible gaseous fuels, when the composition of the gas by mole fraction is known.

When it comes to importing the dialogue into Game Maker Studio, it's as easy as could be. The code in the example project is well commented and is flexible and easy enough to understand to adapt it into any format you'd want. If you are new to GMS you may have some trouble, but if you understand the basics of Game Maker Language, you'll have zero issues.